Vat dyestuffs



Patented I Nov. 7, i022.

harem oafaicao WILHELM BAUER AND ALFRED HERRE, OF OPLADEN,

ASSIGNOBS TO FARBIENFAIBEIKEN 1703M. FRIEDm, KUSEN, NEAR COLOGNE-ON-THE-RHINE, GERMANY.

NEAR COLOGNE, GERMANY,

No Drawing.

To all whom it may concern Be it known that we, WILHELM BAUER and ALFRED Hanan, citizens of Germany, resid- I ing at Opladen, near Cologne-on-the-Rhine, Prussia, Germany, have invented new and useful Improvements in Vat Dyestufi's, of which the followin is a specification.

We have found that new and valuable vat dyestuffs can be obtained by condensin 2.1- naphthooxythiophene with isatins e. g. alogenated isatins, such as 5.7 -dihalogenated isatins.

The reaction proceeds most probably e. g. in accordance with the following equation:

The new dyes are in a dry state reddishbrown crystals with a metallic lustre which are soluble in hot nitrobenlzene with a r dish-brown coloration. They yield with hydrosulfite and caustic soda solution yellow vats dyeing cotton after exposure to air brown shades fast to chlorin and to light.

In order to illustrate the new process more fully the following example is given, the parts being by weight: 220 parts of 5.7- dichlorisatin are dissolved in 5000 parts of hot glacial acetic acid, a solution of 200 parts of 2.1-naphthooxythiophene in 500 parts of glacial acetic acid and then 100 parts of concentrated hydrochloric acid are added. The resultin mixture is heated during one hour on t e water bath. The dyestufi which has separated is filtered 05 after cooling, washed and dried.

7 Application filed February 2, 1922. Qerial 1 30. 583,649.

It has most probably the following formula:

0c. k ls/ t ml crystallizes in brown needles havin a metallic lustre which are dificultly solubfie in concentrated sulfuric acid with a reddishviolet coloration and easily soluble in monohydrated sulfuric acid With a bluish-violet coloration. It dyes cotton from the hydrosulfite vat in brown shades fast to chlorin, washing and light.

On usm isatin or 5.7-dibromoisatin instead of 5. -d1chloroisatin products are obtamed capable of dyeing cotton in brown shades.

We claim l. The new products being vat dyestuii derlvable trom 2.1-naphthooxythiophene and an isatin compound, which dyes are-in a dry state reddish-brown crystals with a metallic lustre soluble in hot nitrobenzene generally with a reddish-brown coloration; and whlch yield with hydrosulfite and cans tic soda lye vats dyeing cotton brown shades remarkable for their fastness to chlorin and to light, substantially as described.

2. The new the formula:

being a vat dye derivable from 5.7 -dichloroiproduct having most probably 2 mamas with a metallic lustre, soluble in concenset ourhsnds in the presence of two subtrated sulfuric acid with a, reddish-wolet scribing witnesses. coloration .and in monohydrrted sulfuric acid with a bluish-violet coloration, and WILHELM BAUER 5 dyeing cotton from the hydrosulfite vat in ALFRED HERRE; brown shades fast to chlorin, washing and Witnesses:

li ht, substantially as described. Emc ROUDEY,

n testimony whereof we have hereunto WALLER BBAUN. 

